Study On The Interactions Between Hawthorn Oligosaccharides And Bovine Serum Albumin

The complex prepared by the interaction of protein and carbohydrate can improve the solubility of protein,enhance the emulsification stability and gelation and other functional properties,and has been widely used in the fields of microencapsulation,edible biofilm materials and improving the quality of meat products.In this study,hawthorn was used as raw material to isolate and extract pectin and prepare pectin oligosaccharides.The interaction between hawthorn pectin oligosaccharides(HO)and bovine serum albumin(BSA)and its mechanism were studied under different p H values,complex ratio and temperature.The results are as follows:1.Hawthorn pectin was extracted by water extraction and alcohol precipitation.The crude hawthorn pectin was separated and purified by DEAE-52 anion exchange chromatography.After separation and purification,the content of galacturonic acid,total sugar,total phenol and protein was 84.08%,91.3%,0.17% and 0.001%respectively.2.In the study on the effect of p H on the interaction of Hawhawn-oligosaccharide-bovine serum albumin complex,when p H increased from3 to 5,the grafting degree of HO-BSA complex increased,resulting in the decrease of particle size,sulfhydryl content,surface hydrophobicity and UV characteristic absorption peak intensity,and the increase of maximum fluorescence intensity and absolute value of Zeta-potential;When p H increased from 5 to 7,the grafting degree of HO-BSA complex was weakened,resulting in the increase of particle size,absolute value of Zeta-potential,sulfhydryl content and viscosity,and the decrease of surface hydrophobicity,UV characteristic absorption peak intensity and maximum fluorescence intensity.3.In the study of the influence of complex ratio on the interaction between Hawthorn oligosaccharides and bovine serum albumin complex,compared with HO or BSA alone,the formation of HO-BSA complex increased its internal sulfhydryl content,viscosity and the characteristic absorption peak intensity of ultraviolet absorption spectrum.As the ratio of the two increases,the particle size,PDI,absolute value of Zeta-potential,turbidity and surface hydrophobicity of HO-BSA complex increased significantly,while SH content,characteristic absorption peak intensity and maximum fluorescence intensity of UV absorption spectrum decreased.As the ratio of the two decreases,the turbidity,surface hydrophobicity and the characteristic absorption peak intensity of UV absorption spectrum of HO-BSA complex decreased,while SH content and maximum fluorescence intensity increased.4.In the study of the influence of temperature on the interaction between Hawthorn oligosaccharide and bovine serum albumin complex,the content of free amino,viscosity and surface hydrophobicity of HO-BSA complex decreased significantly with the increase of reaction temperature in the range of 20-100℃.The absolute value of Zeta-potential of HO-BSA complex increased with the increase of reaction temperature.